Ethyl 2-chloroacetoacetate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 June 2010 - 09 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult substances and mixtures, OECD series on testing and assessment number 23, December 14, 2000.

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl 2-chloroacetoacetate

EC Number:

210-180-4

EC Name:

Ethyl 2-chloroacetoacetate

Cas Number:

609-15-4

Molecular formula:

C6H9ClO3

IUPAC Name:

ethyl 2-chloro-3-oxobutanoate

Constituent 2

Reference substance name:

Chloracetessigester

IUPAC Name:

Chloracetessigester

Details on test material:

- Name of test material (as cited in study report): Chloracetessigester
- Substance type: Clear slightly yellowish liquid
- Physical state: Liquid
- Analytical purity: 93.9%
- Lot/batch No.: 001008
- Expiration date of the lot/batch: 26 July 2010
- Stability under storage conditions: Stable
- Storage condition of test material: At room temperature in the dark
-Stability in water: Unknown
-Solubility in water: Yes, 17 g/L
- Density: 1.18 g/cm3 (20°C)

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

During the final test duplicate samples for possible analysis were taken from all test concentrations and the control according to the schedule below.

Frequency: at t=0 h and t=48 h
Volume: 4 ml from the approximate centre of the test vessels
Storage: Not applicable, samples were analysed on the day of sampling.

At the end of the exposure period, the replicates were pooled at each concentration before sampling.

Test solutions

Vehicle:

no

Details on test solutions:

The batch of Chloracetessigester tested was a clear slightly yellowish liquid with a purity of 93.9% and the substance appeared to be completely soluble in test medium at the concentrations tested.

Preparation of test solutions started with the highest test concentration of 100 mg/l applying a 15 to 18-minute period of magnetic stirring. The lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. During the final test dilutions were prepared from a stirring solution and all test vessels used were incubated for 1 day with the respective test solutions as to prevent any possible adsorption to glass ware. After the pre-incubation period vessels were filled with freshly prepared solutions. All final test solutions were visually clear and colourless.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by acyclical parthenogenesis under specified breeding conditions.
- Source: In-house laboratory culture with a known history.
- Age at study initiation:< 24 hours
- Method of breeding: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 10 litres of medium in an all-glass culture vessel.
- Feeding during test: No

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg/l expressed as CaCO3

Test temperature:

between 19.4 and 20.3°C

pH:

between 5.1 and 8.0

Dissolved oxygen:

between 1.7 and 9.5 mg/l
It should however be noted that especially at the highest test concentration it was observed that oxygen was very low at the study start (1.7 mg/l). The oxygen concentration at the end of the test had increased to a normal value of 8.1 mg/l.

Nominal and measured concentrations:

At the start of the test, the mean measured concentrations were 0.19, 0.31, 0.86, 2.5 and 14.0 mg/l at the nominal concentrations of 10, 18, 32, 56 and 100 mg/l, respectively. The measured concentration after 48 hours decreased to 4.8 mg/l at nominally 100 mg/l. Measured concentrations in samples taken from nominally 10 to 56 mg/l could not be quantified (<0.1 mg/l). It was therefore not possible to determine average exposure concentrations for the range tested. Consequently, results were based on both nominal and initial measured exposure concentrations.

Details on test conditions:

- Type (delete if not applicable): open
- Material, size, headspace, fill volume: glass, 100 ml, normal headspace, 80 ml
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Adjusted ISO medium: the following chemicals (analytical grade) are dissolved in tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands):
Macro salts:
CaCl2.2H2O : 211.5 mg/l
MgSO4.7H2O: 88.8 mg/l
NaHCO3 : 46.7 mg/l
KCl : 4.2 mg/l
The hardness: 180 mg/l expressed as CaCO3 and the pH: 7.7 ± 0.3 after aeration.
- Culture medium different from test medium: yes, for culturing M7 medium is used
OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily
EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EC50 t=24, 48 h and NOEC
TEST CONCENTRATIONS
- Spacing factor for test concentrations:
range finding: 10
main study: 1.8
- Test concentrations:control and 10, 18, 32, 56 and 100 mg/l

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7,)

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

28 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI 24 - 32 mg/l.

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.66 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI:0.52-0.85 mg/l

Effect concentrations 3

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

28 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CI:26 - 32 mg/l

Effect concentrations 4

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 5

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.31 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Behavioural abnormalities: no
- Immobility of control: no immobility was observed.
- Other adverse effects control: no

Results with reference substance (positive control):

The 24h-EC50 was 0.75 mg/l with a 95% confidence interval between 0.56 and 1.0 mg/l.
The 48h-EC50 was 0.36 mg/l with a 95% confidence interval between 0.28 and 0.49 mg/l.

Reported statistics and error estimates:

Calculation of EC50:

The EC50-value was calculated at 24 and 48 hours of exposure from the probits of the percentages of affected daphnids and the logarithms of the corresponding test substance concentrations using the maximum likelihood estimation method (Finney, D.J., 1971: Probit analysis, Cambridge University Press, Cambridge, U.K., 3rd edition).

Any other information on results incl. tables

-

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study Chloracetessigester did not induce significant acute immobilisation (<10%) of Daphnia magna at a nominal concentration of 18 mg/l after 48 hours of exposure (NOEC). This corresponded to an initial measured concentration of 0.31 mg/l.

The 48h-EC50 was 28 mg/l based on nominal concentrations (95% confidence interval between 24 and 32 mg/l) and was already reached after 24 hours of exposure. Based on initial measured concentrations this corresponded to 0.66 mg/l with a 95% confidence interval between 0.52 and 0.85 mg/l.

Executive summary:

-